Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/xsgadem.html
AHELP for CIAO 4.11 Sherpa v1

xsgadem

Context: models

Synopsis

The XSPEC gadem model: plasma emission, multi-temperature with gaussian distribution of emission measure.

Syntax

xsgadem

The xsgadem model is an additive model component.

Description

The model is described at [1] . The set_xsabund and get_xsabund functions change and return the current settings for the relative abundances of the metals. See the XSapec documentation for settings relevant to the APEC model (i.e. when switch=2 ).


Example

>>> create_model_component("xsgadem", "mdl")
>>> print(mdl)

Create a component of the xsgadem model and display its default parameters. The output is:

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.Tmean    frozen            4         0.01           10        keV
   mdl.Tsigma   thawed          0.1         0.01          100        keV
   mdl.nH       frozen            1        1e-05        1e+19      cm^-3
   mdl.abundanc frozen            1            0           10           
   mdl.Redshift frozen            0       -0.999           10           
   mdl.switch   frozen            2            0            2           
   mdl.norm     thawed            1            0        1e+24           

ATTRIBUTES

The attributes for this object are:

Tmean

The mean temperature for the gaussian emission measure distribution, in keV.

Tsigma

The sigma of the temperature distribution for the gaussian emission measure, in keV.

nH

H density, in cm^-3.

abundanc

The metal abundance of the plasma, as defined by the set_xsabund function.

Redshift

The redshift of the plasma.

switch

If 0, the mekal code is run to evaluate the model; if 1 then interpolation of the mekal data is used; if 2 then interpolation of APEC data is used. See [1] for more details. This parameter can not be thawed.

norm

The normalization of the model.

References

XSPEC version

CIAO 4.11 comes with support for version 12.10.0e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.10.0e

Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

models
xsvgadem